Metronome



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METRONOME Filed Sept. 10, 1945 2 Sheets-Sheet l /M/fA/vw? f Fh TRKA F. TORKA July 5, 1949.

METRONOME 2 SheeS-Sheet 2 Filed Sept. lO, 1945 Patented July 5, 1949 UNITED STATES PATENT` GFFICE METRONOME Frank Torka, Seattle, Wash., assigner to Walter J. Terry, Seattle, Wash.

Application September 10, 1945, Serial No. 615,490

1 Claim. 1

The purpose of this invention is to provide a time measuring device for use in typewriting class rooms which is readily adjustable as to cadence and sufciently audible.

The invention is a motor operated rotatable disc having pitch indentations therein with a spring controlled hammer operated by said indentations and adapted to strike a Sounding plate.

Time measuring devices have been used in music and other fields and although these are adjustable they do not produce suicient sound to be heard in a typewriting class-room.

The object of this invention is therefore to provide a sound measuring device which is positively operated and adapted to -produce sufficient sound to be heard in a typewriting classroom.

A further object of the invention is to provide a sound measuring device which is of a simple and economical construction.

With these ends in view the invention embodies a stand, a disc rotatably mounted in said stand, a motor with a belt adapted to rotate said disc, a time indicating plate on said stand, a frame pivotally mounted on said stand having a pointer registering with characters on said indicating plate, a sound plate on said frame, and a spring forming a hammer with one end engaging indentations in said disc, and the other adapted to strike said sound plate as it is actuated by the indentations with the disc rotating.

Other features and advantages of the invention will appear from the following description taken in connection with the drawings, wherein:

Figure 1 is a front elevation of the metronome, with part of one leg of the stand broken away.

Figure 2 shows a side view of the device.

Figure 3 is a plan view of the device with part broken away.

Figure 4 is a detail showing a section through the disc illustrating the end of the spring engaging the indentations thereof.

Figure 5 is a detail illustrating the spring mounting.

In the drawings the time measuring device is shown as it may be made wherein numeral i indicates the disc, numeral 2 the hammer, and numeral 3 the motor.

The disc l is mounted on a stand formed by three legs 4, 5, and 6 through a hub 'l which is rotatably held by a pin 8 on a horizontal section 9 of the stand, as shown. The disc is provided with a peripheral groove I0 by which it is rotated with a belt Il from a pulley l2 on a reduction gear I3 at the end of the motor 3. The

disc is formed with a plurality of indentations ifi arranged in rings of concentric circles with the diametrical pitch of the indentations different in the different circles so that the tempo or cadence may be varied by shifting the hammer operating prong l5 from one circle to another.

The hammer 2 may be shaped as shown with a hub I6 thereof pivotally mounted on a pin l?, and with the prong I5 extending downward from the hub. The hammer is resiliently held by a spring i8 positioned around the pin I1 with one end i9 over the hammer, and the other end 2i] bearing against the bar 2| of the hammer frame 22. The pin l'l is suspended between set screws 23 and 24, having lock nuts 25 and 26, with the points of the set screws extending into centered openings in the ends of the pin. The frame 22 is provided with a hub 21 through which it is pivotally mounted on a pin 28 at the upper end of the leg 4 of the frame or stand, and the forward end oi the frame is provided with a pointer 29 on a hub 30, and a pin 3| with a nut 32 is held in the hub with the pioint thereof extending downward and into one of the holes 33 in an indicating plate 34, the holes spaced to correspond with the concentric circles, and by lifting the nut 32 the @pin 3| may be raised from one hole and moved to another, thereby moving the prong I5 from one set of indentations to another with a'. different pitch. The frame 22 is provided with a sound plate 35 mounted on posts 36, and positioned to be engaged by the hammer 2 as it is operated by the indenta tions.

It will be understood that changes may be made in the construction Without departing from the spirit of the invention. The construction will be readily understood from the foregoing description. In use the motor will rotate the disc and this will operate the hammer to strike the sound plate.

Having thus fully described the invention what I claim as new and desire to secure by Letters Patent, is:

In a time interval indicator, the combination which comprises a horizontally disposed disc having a plurality of spaced concentric sets of indentations in the upper surface, a frame having a centrally disposed vertically positioned hub on which the disc is positioned, supporting posts positioned beyond the periphery of the disc, arms supporting the hub from the posts, a vertically disposed shaft rotatably mounting the disc in the hub of the frame, a. speed indicator plate xedly mounted on said posts and positioned resilient means holding the hammer with theie prong thereof in engagement with the indentae tions of the disc, and means rotating the saiddis'os'- REFERENCES CITED The following refererrces are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 843,621 Mcntire -.n Feb. 12, 1907 1,861,937 s' Philips June 1932 10 2,150,967` Franz Mar. 21, 1939 FOREIGN PATENTS Number Country Date 565,0.11w France Nov. 2, 1923 

